Who pays and why? Costs, effectiveness, and feasibility of HIV treatment as prevention

Treatment as prevention (TasP) has been added to the toolbox of human immunodeficiency virus (HIV) prevention technologies, and countries are at different stages of TasP deployment. In this article we review some of the cost implications and summarize effectiveness data from different settings. Also, we reflect on the affordability and feasibility of programmatic deployment as well as the multiple challenges of maintaining service quality while HIV treatment programs grow in size and complexity. We conclude that in low-resource settings, TasP progress will be very incremental with progressively earlier treatment initiation while working within the capacity and resource constraints of the respective healthcare systems. In the long-term, feasibility will rely on complementary interventions to reduce new HIV infections, such as male circumcision, and on demand creation for early treatment uptake as well as adherence. TasP holds potential for moving us closer to the global goal of ending AIDS.